Hydraulic motor

Abstract

A hydraulic motor having a plurality of cylindrical pistons each of which is slidably mounted in a fluid tight manner along a respective cylindrical bore provided axially through a rotor keyed to a central rotatable shaft, each said piston being thrusted by a pressurized fluid with one end into contact with a flat surface of a toroidal member mounted to rotate about its own axis which is arranged at an angle to the axis of said central shaft, and rotation of said rotor causing each said piston to rotate about its own axis within the respective bore owing to said one end of each piston being shaped as a spherical bowl, the diameter of which is at least 0.7 times the radius of the respective piston divided by the sine of said angle.

What I claim is: 
     
       1. A hydraulic motor comprising a casing; a central shaft extending through said casing and supported by the latter to rotate about its own axis; a rotor housed in said casing and connected to said central shaft for rotation therewith; a plurality of cylindrical bores provided axially through said rotor; a cylindrical piston slidably and rotatably mounted in fluid tight relation to each of said bores; a toroidal member mounted within said casing to rotate about its own axis, and forming an angle with the axis of said central shaft; said toroidal member having a flat surface facing said rotor; a support member supporting said toroidal member in the casing and having hinge means cooperating with said casing and permitting the toroidal member to oscillate about an axis perpendicular to its axis of rotation and to the axis of the rotor; adjustment means being provided for varying said angle by tilting the support member on said hinge means to change the orientation of said flat surface with respect to the axis of the central shaft; one end of each of said pistons cooperating with said flat surface of the toroidal member under the thrust of a predetermined hydraulic fluid in the bore, said one end of each of the pistons having an end face of substantially spherical shape, and said one end of each of said pistons also has a flat circular face traversing the axis of the piston and a significant portion of the end of the piston; said flat face being perpendicular to the axis of the piston and coaxial thereto. 
     
     
       2. A hydraulic motor comprising a casing; a central shaft extending through said casing and supported by the latter to rotate about its own axis; a rotor housed in the casing and connected to said central shaft for rotation therewith; a plurality of cylindrical bores provided axially through said rotor; said axial bores being distributed along two circumferences coaxial to said central shaft, each of said axial bores being disposed on one of said circumferences and corresponding to an axial bore on the other circumference, the axes of each pair of corresponding bores being disposed in the same diametrical plane of said rotor, and the bores of each pair of said bores communicating with each other through a port; a plurality of cylindrical pistons each slidably and rotatably mounted in a fluid type relation in a respective bore; and a toroidal member mounted within said casing to rotate about its own axis, this latter forming an angle with the axis of the central shaft; said toroidal member having a surface facing said rotor, said surface defining a pair of flat annular surface portions concentric of each other and confronting the ends of the pistons in the two circumferences of axial bores; and one end of each said piston cooperating with said flat surface under the thrust of a pressurized hydraulic fluid in the rotor bores; said one end of each piston having an end face of substantially spherical shape, said ports between adjacent bores being disposed in proximity to that of the ends of the bores opposite to the one facing said toroidal member. 
     
     
       3. A motor as claimed in claim 2, wherein of those ends of the bores of each of said pair of bores which are opposite to those ends facing said toroidal member, one communicates with distribution means for said pressurised fluid whereas the other is closed.